Rotary print wheel mechanism with hammering bracket

ABSTRACT

A type wheel or wheels are rotatably mounted between the upper and lower arms of a yoke-shaped member which in turn is drivingly coupled to a rotary shaft for rotating about the axis thereof the type wheel or wheels, and the upper end of a hammering bracket is slidably fitted over the yoke-shaped member so that the striking force or impact is applied through the upper end to the rotary shaft thereby causing the latter to rotate toward the platen.

O Unlted States Patent 11 1 1111 3,823,807 Suzuki 1451 July 16, 1974 ROTARY PRINT WHEEL MECHANISM 3,461,996 8/1969 Kapp 197/111 x WITH HAMMERING BRACKET 3,596,745 8/1971 Waldenburger 197/55 3,695,410 10/1972 Kapp 197/55 [75] In entor: Takaml Su u i, y a, pa 3,739,898 6/1973 Rooney 197/55 1 90 9011 60., 1.111., T okyo, Japan FOREIGN PATENTS OR APPLICATIONS [22] Fiied: Apr. 27, 1973 1,436,730 3/1969 Germany 197/48 [211 App! T 355062 Primary Examiner- Robert E. Pulfrey Assistant Examiner-E. H. Eickholt [30] Foreign Application Priority Data Attorney, Agent, or Firm-Cooper, Dunham, Clark,

Apr. 28, 1972 Japan 47-043165 'Grlffin & Moran [52] 0.8. CI. 197/55, 101/93 Q: 57 ABSTRACT [51] Int. Cl B4lj l/32 A t ype wheel or wheels are rgtgtably mounted be- [58] Field of Search 197/1, 18, 48, 55, fwei'the m arms of a yoke shaped 101/93 178/34 0 member which in turn is drivingly conpled to a rotary shaft for rgtgtinggbout the axis thereof the type wheel [56] References C'ted or wheels, and the upper end of a hammering bracket UNITED STATES PATENTS is s1 idab1 y t:1ttec12y e r the yoke-shaped-member so that 693,208 2/1902 Armstrong 197/55 the 'stfiking force or impact is applied through the 1,079,447 11/1913 Soblik 197/55 X upper end to the rotary shaft thereby causing the lat- Tyberg ter to rotate toward the platen 3,356,198 12/1967 Michelotti 197/18 X 3,405,794 10/1968 Means 197/55 3 Clalms, 3 Drawmg Flgures PATENTED I 51974 SHEEIIBFZ FIG.

llllllllllllllilllll BACKGROUND OF THE INVENTION The present invention relates to a printing mechanism for use with an ordinary typewriter or imputoutput device of an electronic computer, the printing mechanism being mounted upon a carrier movable in parallel with a platen. I

In the printing mechanism of thetype described, the carrier upon which is mounted a type head comprising a type wheel or wheels having a plurality of types arranged in row and column upon the peripheral surface thereof, is moved in parallel with the axis of a platen, and the type head is rotated toward the platen so that a selected character may be printed. Since the type head strikes against the platen great impact is exerted thereon so that a rotary shaft for rotating the type head or type wheel assembly must be increased in diameter. As a consequence the type head is increased in weight, thus adversely affecting the high speed printing operation. In order to overcome this problem there has been proposed a method in which a frame is disposed in parallel with an independently of the rotary shaft so that the impact may be received by the frame and the diameter of the rotary shaft may be reduced. However this arrangement is not satisfactory in practice because of the defects that the types on the type wheel are covered by the frame and the undesired excessive force is exerted to the type head.

One of the objects of the present invention is therefore to provide an improved printing mechanism of the type which is mounted on a carrier movable in parallel with a platen. I

Another object of the present invention is to provide an improved printing mechanism of the type described and in which a spindle or spindles for rotating a type wheel or wheels can be made light in weight in order to increase the typingspeed, and the point of applica-- tion of striking force remains almost unchangedduring the printing operation so that undesired excessive force may not be exerted to the printing mechanism. According to one embodiment of the present invention a yoke-shaped orta"-shaped member, which is drivingly coupled to a hollow spindle, carries a type wheel or wheels, and a hammer bracket is pivotably fixed to a carrier movable in parallel with a platen and has a tip which is formed at the upper end thereof for slidable engagement with the yoke-shaped member. The rotation of the hammer bracket is transmitted through the yoke-shaped member to the hollow spindle so as to strike the type wheel against the platen. The impact is mainly received by the bracket, and a lesser for ce is transmitted to the hollow spindle. The point of application of striking force to the type wheel assembly almost remains unchanged in the printing operation so that no undesired force is produced or transmitted to the type wheel assembly.

The above and other objects, features and advantages of the present invention will become more apparent from the following description of one preferred'embodiment thereof taken in conjunction with the accom panying drawing.

BRIEF DESCRIPTION OF'THE DRAWING I FIG. 1 is a view, partly in sectionand looking from 3 of a printing mechanism in accordance with the present invention;

FIG. 2 is a side view thereof; and 4 FIG. 3 is a diagrammatic view used for the explanationof a type head shifting mechanism thereof.

DESCRIPTION OF THE PREFERRED I EMBODIMENT Referring to FIGS. 1 and 2, a type wheel assembly comprises a plurality of type wheels 1 (four type wheels being shown in the instant embodiment) rotatably mounted between an upper stem 2 and a lower stem 3 fixed to the upper end of a hollow spindle 4 which in turn is drivingly coupled through gears 5 and 6 to a hollow-spindle driving mechanism not shown). Gears 9 carried by the type wheels 1' at the lower ends thereof are in mesh with a gear 8 carried by an inner spindle 7 at the upper end thereof which is fitted into the hollow spindle 4 and is'drivingly coupled to an inner spindle driving mechanism (not shown). When the spindle shaft 4 rotates the type wheels 1 are revolved around the axis of the hollow spindle 4 so that a desired type wheel 1 is brought to the typing or striking position,

type wheel 1 is brought to the typing or striking position., l I

A yoke integral with'a lift lever 10 has its upper arm securely fixed to the upperstem 2 and its lower arm fitted into an annular groove 11 formed around the hollow spindle 4 so that whenthe shift or lift lever 10 is moved vertically the type head assembly and hence type wheels 1 may be moved vertically. As best shown in FIG. 3 the rack 10 of the lift lever 10 is in mesh with a pinion 12 which in turn is in mesh with a toothed segment 13 carried by a lift-lever driving shaft 14. The pitch line of the rack 10 passes. through the center of rotation of a hammer frame 15 to be described in detail hereinafter. The lift lever 10 is extended through the hammer frame 15 in such a manner that its axis of rotation also coincides with that of the hammer frame 15, tll isat m ih stjnt th Pitq q fihslask 1'0 is tangent to the pitch circle of the pinion 12 may be on the axis of rotation of the hammer frame 15. When the lift lever 10 is vertically moved, a desired row of types on a selected type wheel 1 is brought to the typing or striking position.

Referring back to FIGS. 1 and 2, the hammer frame 15 is pivotably fixed to a carrier 17 with a pair of pivot pins 16 and 16'. A hammer bracket 18, which is also pivotably fixed to the pivot pins 16 and 16', has a tip 19 which is fixed to the upper end of the hammer bracket 18 and is in slidable engagement with the side arm of the yoke 10 bridging across the type head assembly. The lower end of the hammer bracket-l8 is pivoted with a pivot pin 18 to a lever 20 which in turn is connected to a pulley 21.

When the pulley 21 is shifted in the direction indicated by the arrow in FIG. 2, the hammer bracket 18 is caused to rotate in the clockwise direction about the character against the platen 22. The reaction force is s y d bi bsh m t ra sq ln rilsias; the "P 19 is in line with the line connecting between the centers of the platen22 and the type face of the selected character, and rotatesabout the axis of the pivot pins 16 and l6"v so thatthe undesired excessive force will not be transmitted to the type head assembly driving shafts. Furthermore as described before the extension of the axis of rotation of the hammer frame 15 passes the point of intersection between the pitch line and circle of the rack 10- and pinion 12 so that even when the hammer frame 15 is inclined the type wheel 1 may be securely arrested in position when a desired character is impressed. When the type striking operation is completed, the lever is returned to its normal position under the force of a spring 23 so that the tip 19 is rotated in the counterclockwise direction and arrested by the yoke member 10.

So far the present invention has been described in connection with a m'ul'ti-type-wheel type printing mechanism, it is to be understood that the preser t in vefition may be also applied to a single-type-wheel type printing mechanism.

What is claimed is:

l. A printing mechanism of the type mounted upon a carrier movable along the axis in parallel with that of a platen of a printer, said printing mechanismcomprismg a. acarrier movable along the axis axis of a platen,

b. a type head assembly mounted upon said carrier in parallel with the 4 and comprising one or a plurality of type wheels around the peripheral surface of each of which are arrayed types in row and column, and driving shafts for driving said type wheel or wheels,

0. a yoke-shaped member joined to one of said driving shafts so as to bridge said type wheel or wheels,

d. a hammer frame to which is fixed anotherdriving shaft and which is pivotably fixed to said carrier,

and e. a hammer or hammering bracket pivotably fixed to said hammer frame and provided with a tip formed at the upper'end thereof for slidable engagement with said yoke-shaped member.-

2. A printing mechanism as defined in claim 1 wherein the axis of rotation of said hammering bracket is made to coincide with that of said hammer frame.

3. A printing mechanism as defined in claim 2 wherein said yoke-shaped member is formed integral of rotation of said hammer frame. 

1. A printing mechanism of the type mounted upon a carrier movable along the axis in parallel with that of a platen of a printer, said printing mechanism comprising a. a carrier movable along the axis in parallel with the axis of a platen, b. a type head assembly mounted upon said carrier and comprising one or a plurality of type wheels around the peripheral surface of each of which are arrayed types in row and column, and driving shafts for driving said type wheel or wheels, c. a yoke-shaped member joined to one of said driving shafts so as to bridge said type wheel or wheels, d. a hammer frame to which is fixed another driving shaft and which is pivotably fixed to said carrier, and e. a hammer or hammering bracket pivotably fixed to said hammer frame and provided with a tip formed at the upper end thereof for slidable engagement with said yoke-shaped member.
 2. A printing mechanism as defined in claim 1 wherein the axis of rotation of said hammering bracket is made to coincide with that of said hammer frame.
 3. A printing mechanism as defined in claim 2 wherein said yoke-shaped member is formed integral with said one of said driving shafts for vertically moving said type wheel or wheels so as to select a desired row of types thereupon, and said one of said driving shafts is so carried by said hammer frame that the center of rotation of said one of said driving shafts is one the axis of rotation of said hammer frame. 